Floating roof



F. D. MOYER FLOATING ROOF' Aug. 11, 1953 Filed Sept. 50 1949 5Sheets-Sheet l F. D. MOYER FLOATING ROOF Aug. l1, 1953 3 Sheets-Sheet 2Filed Sept. 30 1949 Aug. l1., 1953 F. D. MOYER 2,648,457

FLOATING RooF Filed sept. so, 1949 s sheets-sheet 5 Patented ug. 11,1953 FLOATING ROOF Frederick D. Moyer, Chicago, Ill., assigner toChicago Bridge': Iron Co Illinois mpany; a. corporation of ApplicationSeptember 30, 1949SerialNof 118,810

(Cl. 22B-26") 3 Claims. l,

'I'his invention relates to a oating roof for use in aliquid storagetank.

Floating roofs of many types and forms have beenk proposed and usedintanks designed for the storage of volatile liquid-s. In general,` theroofs fall'into two classifications, namely, single deck roofs in whicha iiat` deck of sheet metal is floated'upon the surface 0I" the liquidin the tank or supported above the sur-face by one or more pontcons, anddouble deck roofs. In the double deck forni of construction, two decksare pro vided, one usually in contact with the stored product and theother spaced above the bottom deck to provide an insulating air space.This latter type of roof is particularly useful in areas where highdaily temperatures are encountered and where the product stored is quitevolatile in nature. Where extreme conditions are not encountered, asingle deck roof is more economical to construct and is generallypreferred for use.

The construction of a roof of either the single or double deck typepresents a rather dillicult problem inasmuch as the plates forming thedeck proper must `be supported on temporary framing located within thetank during construction. Such framing is generally constructed of woodbeams supported on temporary wood or metal supports over which the deckplates are laid and welded or otherwise secured together.

A single deck roof of the pan type, that is, one

which supports itself on the liquid by the use of a rim upstandingaround the edge, while being one of the least expensive to construct, issubject to flexing difficulties in that pontoons (which serve not onlyto support the roof but also to Y stiien it) are omitted. Furthermore,pan type roofs are subject to considerable iiexing when resting onsupports on the bottom of the tank when the tank is empty.

I have invented a pan type floating roof which 'because of itsparticular construction is not only more simple to assemble initiallybut also possesses great resistance to flexing during all phases ofoperation.

The invention will be described in conjunction with the accompanyingdrawings in which Fig. l is a top plan view of a floating roof tankincluding the roof of this invention.

Fig. 2 is a side elevation of the apparatus shown in Fig. 1 with thelower portion of the tank broken away;

Fig. 3 is a vertical section, broken into segments, through a portion ofthe roof;

Fig. 4 is a top plan view of the right hand portion of Fig. 3;

Fig. 5' is a vertical section along line 5-5 of Fig.' 3; 'and Fig. 6 isan enlarged detailed view ofa portion ofthe trusswork on the roof.

Referring now to the drawings, I show a iloating roof tank I9 having apan type roof II constructed according to this invention. locatedtherein; The roof comprises a nat deck portion I2 supported on aplurality of .radial girders i3. The gird'ers,v a number of which. areprovided, radiateoutwardly fromthe center I 4 of the roof.

A circular rim I5 is secured to the. outer edgesv of the, girders. andthe deck and-is supported in upstanding position-above the. deck-bytriangular plates IShaving, one edge welded' to the rim and another`edgeY welded to the deck. Av plurality of inner. posts I'I and outerposts I "IciV extend through they deck. and through the girders and havetheir lower end portions I3 located beneath the deck and girderstructure. Each post consists of a pipe, member I9 which extends throughthe deck and girdersandhasa pair of angleirons 2U. wel'declto. its upperend. Asecond pipe, section 2I` is welded tothe upper ends of the angleirons and'is. provided. with brackets 22 and 23 extending therefromalongaradiusof the deck.

A1 truss system 2liy extendsv from a central ine-- tallic disc 25positioned. on the upper end of al postl26`extending from. the centerportion of the deck. Each truss system consists of a first cable 27extending between the disc 25 and each inner post Il, a second cable 28extending between the post I I and the post I la, and a pair of cables29 and 30 extending divergently outward from the outer post I'Ia to twoof the plates I6.

A trusswork 32 connects the posts II to each other and consists of steelrods 33 welded or otherwise secured to the lower portion of a post I'Iand extending diagonally upward to the upper portion of an adjoiningpost I7. As can be seen in Figs. 2 and 6, alternate pairs of posts I'Iare provided with the X type trusswork shown in the right hand portionof Fig. 6, While intermediate pairs of posts I'I are connected by asingle rod 33 as seen in the left hand portion of Fig. 6.

Means are provided for preventing the roof from rotating within the tankduring its operation, the means comprising in the embodiment shown achannel member 34 running vertically from the top to the bottom of thetank engaging the sides of a cut-out portion 35 in the roof.

In constructing the roof of this invention, the temporary framingmembers 36 are first placed into position on the bottom 31 of the tank.The temporary framing members may be left in the Comb] tank to supportthe roof during periods of operation When it is not floating on theliquid or they may be subsequently replaced by permanent supports ofsimilar construction. Next, the radial girders I3 are located inposition on the supports and the plates forming the deck l2 are laidthereon and welded or otherwise secured thereto. Thus, it can be seenthat all or practically all of the temporary girders needed in theframing for constructing the roof are eliminated and the radial girdersused for framing eventually become an integral part of the roof. Theplates I6 may then be secured in position on the deck, the rim attachedand the other details of the roof completed.

In the operation of the roof and trusswork described herein support theroof against the truss system serve not only to 4 a central post withall the inner posts being equidistant from the central post, a trussworkinterconnecting the inner posts and a truss system connecting radiallyaligned posts with the rim and being connected together at the center ofthe roof above the deck.

2. A circular loating roof comprising a plurality of girders connectedtogether and adapted to resist torsional stresses in the roof, a deck onthe upper side of the girders, a circular rim attached to the outer endsof the girders and upstanding from the deck, a plurality of postsattached to each girder and extending above and below the deck, saidposts including an inner post, an outer post attached to each girder anda 'central post with all the inner posts being equidistant from thecentral post, the outer posts

